Chromatographic methods generally are used to separate and/or purify molecules of interest such as proteins, nucleic acids and polysaccharides from a mixture. For example, affinity chromatography involves passing a mixture over a matrix having bound to it a ligand specific for a target molecule in the mixture. Upon contacting the ligand, the target molecule is bound to the matrix and is retained from the mixture. Affinity chromatography provides a purification method that is highly specific, fast, economical and high yielding.
Protein chromatography methods are useful for detecting biomarkers associated with specific diseases in tissues and biological fluids. Early detection of these biomarkers is generally critical for successful treatment of disease, and the detection of these biomarkers is increasingly utilized as new biomarkers are discovered. However, biomarkers are usually present in very low concentrations in biological samples. Commercially available particles for affinity chromatography, for example, such as agarose beads and magnetic beads, are unsuitable for isolating trace amounts of these biomarkers. Accordingly, there is a need for new protein chromatography materials and methods to recover biomarkers and other target molecules present at low concentrations from solutions, in particular biological solutions such as serum or cell lysates.